ANA repaired three burnt circuit boards prior to 787’s grounding

All Nippon Airways Co., the biggest operator of Boeing Co. 787s, repaired three damaged circuit boards last year on Dreamliners, the aircraft that was grounded worldwide this year after lithium-ion batteries caught fire.

Of three circuit boards that burned, one that was damaged in April had to be replaced, Shozo Tsue, secretary general of the Japan Federation of Aviation Workers’ Unions, told reporters in Tokyo today. ANA fixed three circuit boards last year safely before flights, Megumi Tezuka, an ANA spokeswoman said by telephone.

Tsue said he doesn’t know whether there is a link between circuit-board damage and the battery fires and that he has sent a letter to the nation’s transport minister asking that “issues” uncovered in the 787 be reconsidered. Boeing’s Dreamliners have yet to fly commercially after the January grounding, the first time in 34 years an entire airplane model has been pulled from service.

“The circuit board case on April 7 was serious and caused damage to the surrounding area,” Tsue said.

Investigators have yet to say they’ve found the causes of a lithium-ion battery fire on a Japan Airlines Co.-operated Dreamliner in Boston in January and that for an emergency landing of an ANA 787 later that month.

Boeing last month submitted a proposed permanent solution for the battery problem to the U.S. Federal Aviation Administration to get the plane back in service. The plan will require extensive testing and approval before regulators end the plane’s grounding, the U.S.’s top aviation official said.

“We can’t say if there was any connection between the circuit boards and the battery, but there have been lots of problems with the electrical system,” Kazuo Harigai, assistant secretary of the Japanese aviation workers’ union, said at the press conference today.